When we are driving at an intersection, if the traffic light turns red, all cars and pedestrians have to stop and wait. Thus, the red lamp is used as a warning signal which makes people pay attention to the dangerous situation. Likewise, if a city has a high crime rate and its social order is getting worse, how do we use "red lamp" to express this idea in a natural way?
The red light tells you to stop. It's not a danger or caution signal.
In America, we would give a "red light" only to those things that are in our power to stop. You can give the red light to Mr. Johnson's business proposal. You can't "red light" street crime.